In Calgary, the blizzard could deliver 15 to 30 centimetres of snow, Environment Canada says.
Blowing snow is reducing visibility on roads in Calgary and on highways outside the city.
The blizzard warning covers all of central and southern Alberta’s major communities, including Red Deer, Brooks, Airdrie, Lethbridge, and Medicine Hat and Drumheller.
“The worst conditions are expected near and along a line from Red Deer through Strathmore and south towards Lethbridge, with northerly winds becoming as strong as 50 gusting to 80 km/h and visibilities near zero at times,” Environment Canada said.
The weather has also forced numerous flight cancellations at the Calgary International Airport.
Strathcona-Tweedsmuir School in Okotoks is closed Monday.
The intense winter storm has been moving down from northwestern Alberta since Saturday.
The snowfall is expected to taper off on Tuesday, but the cold air will stay entrenched over the province for the whole week, Environment Canada said.
Most of southern Saskatchewan is also under a winter storm warning.